As another reviewer pointed out this bit of cold war propaganda (pro Soviet) was absurdly impossible. An axis soldier would have been shot period or arrested as a spy and killed slowly in a prison camp.
So you have to dismiss the story as absurd as it stands and place it in Iran or Finland or some place where it could have happened. Or just suspend your disbelief.
Once you do that you can enjoy this bit of really well done maudlin romance. Loren had to be at the height of her classy beauty in this film (before she was aged for the story).
I loved the part where she spots an Italian man---the only handsome well dressed stylish man in any of the Russian scenes. Of course Loren herself is like a super nova star compared to the kerchiefed thick legged Russian women. Italian audiences must have loved this film.
I give it a 7 as it is very enjoyable once you deal with the absurd story and the maudlin nature of the movie. As another reviewer states what is so wrong with first class maudlin??